1. Technical Field
The present disclosure relates to a motor equipped with dampers for reducing the vibration and noise of a rotator, and more specifically to a motor equipped with dampers for reducing the vibration and noise of a rotator, in which a stator block provided in the motor is provided with dampers for preventing shock and noise, thereby reducing vibration and noise generated when the rotator is rotated.
2. Description of the Related Art
Unless otherwise indicated herein, the content described in this section is not prior art to the claims in this application, and is not admitted to be prior art by inclusion in this section.
Recently, in order to increase energy efficiency, three-phase brushless DC motors, which are controlled by inverters, have been increasingly used in household appliances, such as automobiles, air conditioners, washing machines.
A brushless DC (BLDC) motor is also called a commutatorless motor. A BLDC motor is a motor which is driven to generate torque by switching current flowing through a stator winding through electronic circuit switching using power switching semiconductor devices, such as transistors, MOSFETs, and insulated gate bipolar transistors (IGBTs), instead of brushes and a commutator, which are important components of common DC motors.
Accordingly, brushless DC motors have current-to-torque and speed-to-voltage characteristics similar to DC motors in the structure of synchronous motors. Due to high efficiency and high power density, brushless DC motors are increasingly being used in applications ranging from home appliances to industrial apparatuses.
Three-phase brushless DC motors can more easily control torque, has higher efficiency, and are more advantageous in terms of noise than single-phase motors. Accordingly, most large loads are handled in a three-phase way. In such a brushless DC motor, three coils are disposed to face a permanent magnet, i.e., a rotor, as a stator so that the three coils have an electrical phase difference of 120 degrees. When the stator coils having respective phases are selectively energized through switching elements, the rotor is rotated by the magnetic force acting between the magnetic poles of a magnetized core and the permanent magnet.
Such brushless DC motors are used as drive sources for blower motors which are used in air conditioners for vehicles. An example is disclosed in Korean Patent No. 10-1169044 of patent document 1.
The blower motor disclosed in the above document includes: a stator block 10 configured such that a core 12 around which a coil is wound is fastened and installed in the upper outer portion of the inside of a cover 11 provided above the stator block 10; a printed circuit board (PCB) 20 fastened and installed below the stator block 10 inside a motor housing 22 while being associated with the core 12 via a terminal 21; a shaft 30 installed inside the stator block 10 such that the shaft 30 can be freely rotated via an upper bearing 13 and a lower bearing 14; and a rotor 50 configured to include a magnet 40 which is fastened and installed onto the lower end portion of the shaft 30 by a fastening washer 41 and which is rotated along with the shaft 30 when the shaft 30 is rotated.
In this case, the motor housing 22 includes an upper cover and a lower cover. The upper cover and the lower cover are coupled by means of a force-fitting method using protrusions and depressions configured to receive the protrusions or a screw fastening method using bolts or the like. For this purpose, the upper cover and the lower cover are provided with fastening portions to which one of the fastening methods is applied.
In this case, the base surface of the stator block 10 is commonly located in the lower side of the upper cover, and a heat sink is commonly located in the upper side of the lower cover.
However, in the motor having the above-described structure, the stator block 10 is provided in the state of being in contact with the upper cover and the lower cover, and thus a problem arises in that vibration shock is directly applied when the rotator is rotated, which results in a problem in which the efficiency of a motor is degraded.
Furthermore, the vibration and noise generated when a rotator is rotated are not cancelled in the motor having the above-described structure. For this purpose, there is a need for an innovative scheme for suppressing the generation of vibration and noise without a significant change in a conventional structure.